Police investigating the murders of five women are examining CCTV footage and may release images showing the last known movements of one of them.
Prayers were said for the dead women at a church service
Det Chief Supt Stewart Gull said he was confident of finding footage of prostitute Anneli Alderton.
Assistant Chief Constable Jacqui Cheer said Miss Alderton was three months pregnant when she was killed, but this was not a factor in the investigation.
ACC Cheer added police were tracking 50 to 100 suspects.
She said: "Miss Alderton was three months pregnant. But we do not regard that as having any relevance to the inquiry - however sad it may be."
She renewed appeals for people in Ipswich to come forward with information adding that officers wanted to track Miss Alderton's final movements..
ACC Cheer explained that the suspects were in different groups, split between those being spoken to and those who are still to be questioned.
She added: "A good way to describe the progress we are making would be to compare the investigation to a jigsaw.
"We have constructed the edges, now we have to fill in the middle."
Meanwhile, Det Chief Supt Stewart Gull said: "We are looking at many hours of CCTV footage.
"We hope to get footage of Anneli - we know she caught a train in Essex last week."
Police are considering staging a reconstruction of the last known movements of one of the women in the hope of jogging people's memories.
On Friday the fifth body found was confirmed as that of Annette Nicholls, 29, who worked as a prostitute.
Her body was discovered naked at Levington near Ipswich, but a post-mortem examination failed to reveal exactly how she died.
The other four murdered women are Gemma Adams, 25, Tania Nicol, 19, Anneli Alderton, aged 24 and Paula Clennell, 24.
Later on Saturday police will appeal for help at the start of Ipswich Town's football match against Leeds United.
Players and spectators will observe a minute's silence for the victims, and Ipswich officials said police had offered women safety advice in the match programme.
On Friday, prayers were said for the women and their families at a church service at Copdock, a village close to where two of the bodies were found.
Suffolk's chief constable Alastair McWhirter has said his force faced "incredible challenges".
But he said his officers remained determined to carry out investigations "thoroughly and quickly", and morale remained high.
Police said all the women were found naked but said none had been sexually assaulted.
Toxicology tests are being carried out on the bodies of all five women, who were all drug users.
Detectives have received more than 7,000 calls from the public.
Suffolk Police are being helped by 26 other forces, and 250 officers are working on the five murder inquiries.