Description A justice campaigner who performed a sex act in Heaton Park and was found with sick images of children has been jailed.Former NHS worker Joanne Foster, 44, pleaded guilty to a series of sexual offences after being arrested in April 2017 with her then boyfriend, Gary Keenan, 43, following a police swoop at the home they shared.Chester Crown Court heard that Keenan's mobile phone also contained downloaded indecent images of children.There was also a picture of Foster exposing herself in Heaton Park. Keenan had encouraged her to engage in high risk and sometimes illegal sexual activity, prosecutors said.The court was told during a sentencing hearing on Friday how Foster had become a campaigner for tougher manslaughter sentences in 2009 after her long term partner died following a 'one punch' attack during a night out in Macclesfield.In the raid in April last year, devices belonging to Keenan were also seized and hundreds of indecent images of children and illegal pornographic images from the internet were found.Prosecutor Sarah Badrawy said: Some of the pictures and videos show Foster engaging in sexual activity and having sex with multiple males outdoors. One set of pictures of Foster, taken by Keenan, shows her in Heaton Park in Manchester, wearing a white dress and exposing [herself].Foster, of Percyvale Street, Macclesfield, pleaded guilty to possessing 16 Category A pictures, 18 category B and 69 category C indecent images of children under 16.Keenan admitted having 159 category A, 231 category B and 536 category C indecent images of children along with 463 extreme pornographic images and 13 prohibited images in the form of animations.Miss Badrawy said that an image recovered showed Foster with paedo s*** written on her bottom. She added that after starting the relationship, Keenan referred to Foster as his product and encouraged her to engage in high risk and sometimes illegal sexual activity.The court heard that Foster, a former NHS clerical worker, blamed her partner for the actions, saying the former soldier downloaded the images to her phone.But it was said that in police interviews the pair blamed each other.Foster had earlier also admitted one count of possessing indecent images of children and two counts of outraging public decency.The court heard that in 2009 Foster had lost her long-time partner when he died following in a one punch attack during a night out in Macclesfield.In the aftermath she became a campaigner on the dangers of drink fuelled trouble and lobbied for tougher sentences for manslaughter cases.Judge Patrick Thompson jailed Foster for 15 months and Keenan, recently of Altrincham, for two-and-a-half years.