Photographs recovered during an investigation into suspected dissident republican terrorism appeared to show targeting of Merseyside Police Headquarters, the High Court heard today.
Police also seized a deactivated sub-machine gun, explosives and so-called Anarchist's Cookbook detailing how to make bombs during searches of a husband and wife's home in Derry.
Details emerged as bail was granted to one of the accused, 32-year-old American woman Lesley Concannon.
Her mother and brother, who flew in from West Virginia for the hearing, were accompanied by a representative from the US Conmsulate.
Concannon, a mother-of-one who now teaches Zumba dance classes in the city, faces charges of possessing PETN high explosives with intent to endanger life, and and having articles for use in terrorism.
She was arrested and charged along with her 39-year-old husband Kevin Barry Concannon following police raids on their home at Beechwood Avenue, Derry last week.
Searches were carried out as part of ongoing investigations into the discovery of four mortar bombs in March.
Opposing Lesley Concannon's bail application, a prosecution lawyer said police believe the couple are linked to dissident republican activity.
A laptop computer taken from the home led to the discovery of photos taken earlier this year which appeared to depict a show of strength involving three masked men holding weapons and a gun.
It was claimed that another 22 photos appeared to show the targeting of Merseyside Police HQ.
The judge was told Mr Concannon admitted taking the pictures while in Liverpool with his wife last year, claiming he did so due to an interest in the building's size.
An illegal document known as the Anarchist's Cookbook was also recovered from the computer, according to the prosecution.
It provided detailed instructions on how to make explosives, bombs and sets out the ingredients required.
More than 30,000 search entries were identified on the laptop, the court heard.
Requests included "Can I take gun magazine airplane" and "Legal to import gun airplane UK".
The PETN explosives were found in a coal bunker at the rear of the house.
Two days later police returned to the rented property and found a deactivated Yugoslavian M56 sub-machine gun.
A set of new number plates and a coffee grinder box containing magnesium ribbon aluminium filings were located in a spare room.
Documentation of alleged intelligence gathering on suspected drug dealers was discovered hidden in the sleeve of a child's DVD case, the court heard.
Battery springs and tubing similar to that used in explosive projectiles was also seized.
Concannon denied any knowledge of the explosives or machine gun, or of having carried out the computer research.
She told police someone must have climbed over the wall and put the munitions in the coal bunker.
Her barrister, Ivor McAteer, rejected prosecution claims that she may flee if released, pointing out that she had returned to her home after police first searched it.
He told the court his client works as a Zumba dance instructor, taking classes five days a week while her husband looks after their daughter.
Having obtained a degree in marketing at university in West Virginia, she moved to Northern Ireland and got married in 2011.
Stressing her clear criminal record, the lawyer added: "She indicates that she knows nothing, nothing about this activity."
Although he held that a prima facie case has been established, Mr Justice Stephens decided to grant bail on condition that £25,000 in cash sureties are lodged.
As Concannon gasped with relief on the video-link screen, the judge ordered that passports for the accused and her daughter must be surrendered.
He banned her from leaving Northern Ireland and directed that she must report to police daily.
Concannon was also prohibited from using any computers or mobile phone.
The judge added: "She is to keep a diary of her daily activities and any contacts she has, including dates and names, and make that diary available for inspection by police if required to do so."